When you have multiple record-triggered flows that are configured to run before the record is saved on the same object, the order of flow execution is unpredictable. This means that you cannot guarantee which flow will run first or last, or how they will affect each other's field updates. Therefore, you should avoid creating multiple before-save flows on the same object and instead consolidate them into one flow if possible. Reference: https://help.salesforce.com/s/articleView?id=sf.flow_considerations_recordtriggered_before.htm&type=5

Contacts to Multiple Accounts is a feature that allows administrators to relate a contact to multiple accounts without creating duplicate contacts for each account. This feature is useful for scenarios where a contact has business relationships with more than one account, such as consultants, brokers, or loan advisors. By setting up Contacts to Multiple Accounts for loan advisors at DreamHouse Realty, administrators can track which loan advisors work with which customers and which accounts without creating duplicate contacts for each account. Reference: https://help.salesforce.com/s/articleView?id=sf.contacts_multiple_accounts_overview.htm&type=5